| 摘要 |
PROBLEM TO BE SOLVED: To secure reliable sealing of a gas circulation path without in contact with the air outside even to gaseous species having high adsorptivity and high corrosion, gaseous species having high reactivity or the like with a simple configuration, and to configure a reliable seal part reduced with a sealing area and formed with a flat margin on the sealing surface by low torque.SOLUTION: A packing for connecting a gas circulation part includes: an opening 1 provided at the center; a projection 2 setting the opening 1 as one end 2a, and having a flat surface 2b with a thickness 2d and a facing length 2L; and a side 3 setting a step 3a provided on another end 2c of the projection 2 as one end, and having a flat surface 3b with a thin wall thinner than the projection 2 and a length 3L at least in a part, wherein a seal is formed by engaging at least one of connection members at one end 2a of the projection 2 and the flat surface 2b, and also the seal is formed with at least another one of the connection members and a corner 2c formed on another end of the projection 2. |
